October Audio F Division Sub Octave Drive

If you are looking to give your guitar sound some extra low-end depth in a synthy kind of way, the October Audio F Division might be what the doctor ordered. It’s a device that mixes an overdrive circuit with not one but THREE switchable sub octaves. You got that right, the lowest one transposes your signal three octaves lower.

The tree toggles named “1, 2 and 3” allow you to switch on and off the octaves, while the two huge but very cool looking knobs let you set the balance between the drive and the transposed sound, which by itself sounds like a square wave bass fuzz.

The Drive only has one knob that gets you quiet overdriven to louder distorted tones (clean is not an option, unless you turn your guitar volume down a lot, but that’s not what this pedal is supposed to do).

However, the heart of the circuit is the sub-octave engine, which can produce smooth synth tones that get increasingly glitchy below the 5th fret, and offers a variety of synth fuzz tones that can get extremely thick when all three octaves are on.

Check out how it sounds in this launch video.

October Audio F Division Sub Octave Drive, Builder’s Notes


Yeah, F that division stuff!!! Wait, we actually have nothing against math. Some of us have fond memories of multivariate calculus and differential equations… The “f” here is for frequency and we’re chopping your signal not by 1, not by 2, but down to 3 octaves lower! f division is a monophonic sub octave synthesizer with ridiculous rump-shaking bass content!

INSPIRATION: You know those punchy, funky leads and bass lines that can carry an entire song, but you might not even be able to tell what instrument is responsible? That’s what we’re going for here!

CIRCUIT SCIENCE: Input signals are amplified and introduced to a CMOS counter/divider that divides by 2 at each step, cutting the previous frequency in half. There are 3 possible divisions, meaning 3 octaves down form the source. Each toggle is a sub octave and can be on or off in any combination. Two mixer knobs control the ratio and overall volume of the sub and drive sound. The drive is split from the CMOS input and has a crunchy, somewhat synthy sound on its own.


A destructive drive to shatter your routine sounds!

The sub octaves alone sound like square wave bass fuzz and track all over the fretboard, with increasing glitchy-ness below the 5th fret. One octave down is like having a bass player with you, and adding more to that brings out an analog synth vibe.

A 3rd sub octave may seem like a ridiculous idea for guitar, and it is! By itself, it’s a sputtering engine, like a muscle car parked on your pedalboard. In combination with the other octaves, the base tone will sing in contrast to that lowdown 3rd octave!

Note: This can be a loud pedal; plenty of volume is on tap!

Quick settings: Here are some starter ideas!

Implied upper octave: Octaves 1 & 3 on, sub and drive equal
Synthetic chemistry: All octaves on, drive about half volume of sub
Saucy leads: Octave 1 on, sub about half volume of drive
Love dumpster: Octave 3 on, sub and drive equal